Power & Current Converter
Everyday unit conversions in one place: watts, kilowatts, kVA, horsepower and line current. Enter a value in any one box and the rest follow. Three-phase current uses I = P / (√3 × V × pf); single-phase uses I = P / (V × pf).
Converted
Kilowatts--
Watts--
Apparent power--
Horsepower--
Line current--
Formula used--
A note on kW and kVA. Kilowatts are the real power a load actually turns into work and heat. kVA is the total the supply has to deliver, including the reactive part a motor draws and gives back every cycle. Cables, switchgear and generators are sized on kVA, not kW (which is why a 10 kW motor needs more than a 10 kVA supply).
AC Power & Conversion FormulationBS 7671 Appendix 4 & Fundamental AC Electrical Principles
AM2 PORTFOLIO & DESIGN AUDIT FORMATTRANSPARENT FIRST-PRINCIPLES MATHS
Worked example: A 7.5 kW three-phase motor operating on a 400 V supply with a power factor of 0.85:
Apparent Power (kVA) = 7.5 / 0.85 = 8.82 kVALine Current I = 7500 / (1.732 × 400 × 0.85) = 12.7 AHorsepower (hp) = 7.5 / 0.7457 = 10.1 hp
Conversions only. Nothing here accounts for motor efficiency: a motor nameplate kW is the mechanical output, so the electrical input is higher. Use the motor calculator for that.